<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        body{
            height: 3000px;
            background-image: url(sms.jpg);
            background-repeat: no-repeat;
            background-position: center top;
            /* 背景可以滚动 */
            /* background-attachment: scroll; */
            /* 背景固定不能滚动 */
            background-attachment: fixed;
        }
    
        p {
            font-size: 50px;
            color: green;
        }
    </style>
</head>
<body>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
</body>
</html>